Medical sensor devices, such as internal probes that are inserted into a body cavity or under the skin of a patient in order to monitor biological parameters, are well known in the art. Typically, such devices comprise a housing including at least one monitoring element such as a pressure sensor, a light emitting device and associated detector, an ECG sensor, or other vital sign monitoring device. One particular example of a medical sensor device is fetal sensor, such as that described in U.S. Pat. No. 5,425,362. Fetal sensors are inserted into the uterine wall of a mother to noninvasively monitor the condition of a fetus, a mother, and a placenta.
One problem associated with known medical sensor devices is that they have a limited life span. Sensor devices are prone to wear through repeated use or through extended use over a period of time. Problems associated with such overuse include spurious readings as internal wires and connectors become loose. More importantly, sensor devices that are used repeatedly or over an extended period of time are prone to break. Once such an incident occurs, it is often difficult to determine when the sensor failed, or to track the cause of such an occurrence.
To prevent these problems, medical clinicians may limit the number and duration of uses of a given medical sensing device through an equipment log or other manual system. While such systems may be effective in certain circumstances, they rely heavily on manual records, which are time-consuming and difficult to maintain, particularly since the cooperation of a number of clinical personnel is required. In busy hospital settings, and especially in emergency situations, such systems are difficult to manage and are easily overlooked or ignored.
There remains, therefore, a need for a medical monitoring system that can automatically limit the usage of medical sensor devices. Such a system would preferably limit the duration or number of uses of a given medical sensing device to a predetermined limit value. Preferably, the medical monitoring system would also provides additional functions, such as error checking, time and date stamping, and security checking.
It is therefore an object of the invention to provide a medical monitoring system that can limit the number of times a medical sensor device is used.
It is another object of the invention to provide a medical monitoring system that can limit the duration of the use of a medical sensor device.
It is still another object of the invention to provide a medical monitoring system that provides a time and date stamp to identify monitoring processes performed by monitoring equipment.
It is a still further object of the invention to provide a medical sensor device that can store information regarding the duration of use of the device.
It is another object of the invention to provide a medical monitoring device that can store information regarding the number of times the device has been used.
It is a yet further object of the invention to provide a medical monitoring system that can provide product identity of an associated medical sensor device.
It is still another object of the invention to provide a medical monitoring system that includes a security function for verifying the identity of attached sensors.
It is yet another object of the invention to provide a medical monitoring system that includes a security function to prevent tampering with stored data.